Dealing a blow to a pact that has been bottled up in the Senate for more than a year, the Tennessee senators said they fear the international disabilities pact will weaken U.S. disabilities law. Former Sen. Bill Frist and others tried last month to win over Corker, the top-ranking Republican on the Senate Foreign Relations Committee, arguing that the treaty essentially extends the 1990 Americans with Disabilities Act to other nations.

But Corker and Alexander indicated two committee hearings held in November had not changed their mind.

“I’m unable to vote for a treaty that could undermine our Constitution and the legitimacy of our democratic process as the appropriate means for making decisions about the treatment of our citizens,” Corker said.